The present invention relates to an adjustable spacer, particularly for rolling bearings, and to a support assembly, particularly a vehicle hub-axle assembly, implementing the same.
On known vehicle wheel support assemblies, the hub, depending on the stress pattern involved, is fitted idly to the axle (connected to the vehicle suspension) by means of a pair of oblique rolling bearings, the inner rings of which are locked axially on to the innermost member of the assembly, in this case the axle. More generally speaking, on mechanical connections between rotary components, provision is usually made for support assemblies featuring a pair of rolling bearings locked axially in relation to one of two concentric, mutually rotating members. On known support assemblies of the aforementioned type, the rolling bearings are locked axially by inserting a rigid spacer and gripping the bearings between a fixed shoulder on one of said members, e.g. the axle, and a fastener, e.g. a nut, ring nut or retainer ring, fitted on to the axle itself. Particularly in the case of hub-axle assemblies, the use of rigid spacers of fixed predetermined axial length creates numerous assembly problems, due to the fact that, for the oblique bearings to operate correctly, these must be positioned axially to a high degree of precision for eliminating any clearance between the rings and rolling bodies of the same. On account of the machining tolerances involved, however, mutual axial positioning of the bearings cannot always be assured, despite accurate machining of the bearing ring surfaces contacting the spacer, and/or axial clearance may exist between the bearing components. At the assembly stage, therefore, the axial position of the support assembly bearings must be adjusted using calibrated shims, which means first assembling the rigid spacer, accurately measuring the clearance involved, dismantling the assembly, and reassembling it with the required calibrated shim.